Catasetum

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Catasetum
Catasetum-saccatum.jpg
Catasetum saccatum
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Cymbidieae
Subtribe: Catasetinae
Genus: Catasetum
Rich. ex Kunth
Type species
Catasetum macrocarpum
Synonyms [1]
  • CatachaetumHoffmanns.
  • CuculinaRaf.
  • MonachanthusLindl.
  • MyanthusLindl.

Catasetum, abbreviated as Ctsm. in horticultural trade, is a genus of showy epiphytic Orchids, family Orchidaceae, subfamily Epidendroideae, tribe Cymbidieae, subtribe Catasetinae, with currently 200 accepted species, [2] many of which are highly prized in horticulture.

Contents

Species of the genus Catasetum occur from Mexico to Argentina, including much of Central America, the West Indies, and South America. The largest number of species is in Brazil. [1]

Biology

They have thick, cigar-shaped pseudobulbs which are clustered. The leaves are pleated in the upper part and deciduous. The pseudobulbs become spiny after the leaves have dropped.

Pollination

Eulaema cingulata orchid bee showing pollinia attachment points of C. saccatum and C. discolor Eulaema cingulata with Catasetum saccatum and Catasetum discolor pollen atttachment locations.png
Eulaema cingulata orchid bee showing pollinia attachment points of C. saccatum and C. discolor

The inflorescence is borne on the basis. It consists of very fleshy flowers that are unisexual, which is very unusual for orchids. The colorful male and yellowish-green female flowers are typically situated on different plants, a phenomenon known as dioecy. Which type of flower a plant produces is determined by the conditions under which it grows. Male and female flowers are markedly different in size and color. Initially, taxonomists thought they were dealing with different species, a puzzle which Charles Darwin resolved when writing Fertilisation of Orchids . [3] [4] There are rare cases in which a single plant in intermediate conditions will produce both male and female flowers.

Illustration of C. saccatum's (C) column cross section and (D-E) pollinia Darwin - The various contrivances by which orchids are fertilized by insects (1877) - Fig 29.png
Illustration of C. saccatum's (C) column cross section and (D-E) pollinia

The male flowers have a remarkable technique for the ejection of the pollinia. Sack-shaped Catasetum ( Catasetum saccatum ), a tropical South American species, discussed by Darwin, actually launches its viscid pollen sacs with explosive force, when an insect touches a seta. He was ridiculed for reporting this by the naturalist Thomas Huxley. [5]

A and B Larsen orchids - Catasetum tenebrosum 1006-20.jpg
Male flowers
A and B Larsen orchids - Catasetum tenebrosum female Dscn3259.jpg
Female flowers

Growth

In habitat, these plants predominantly grow as epiphytes in very wet forests. Species of this genus all host wood-devouring mycorrhizal fungi which supplement the plants' nutrition by breaking down decomposing wood. Most of these species have a prolonged saprophytic stage in decomposing wood as seedlings before developing leaves and photosynthesis. Fungi which break down wood require a nitrogen source since wood is primarily composed solely of hemi-cellulose, cellulose, and lignin and lacks nitrogen, and these plants are heavy feeders with high nitrogen requirements typically.

Many of these species are known to germinate in ant nests high in the canopy and host ant colonies, which provide the plants with an abundant supply of nitrogen, and they also host ants in cultivation frequently. [6] Most of these species are considered moderately difficult to maintain in cultivation without a greenhouse or Wardian case and some of them defy cultivation. Most of them cannot tolerate dryness and some of them have very specific temperature requirements. Some of these species are ant plants and attract ant colonies and can become a nuisance in cultivation.

Species

Catasetum barbatum Catasetum barbatum 009.jpg
Catasetum barbatum
Catasetum deltoideum Catasetum deltoideum - fl 1.jpg
Catasetum deltoideum
Catasetum complanatum Catasetum complanatum DSC 0935.jpg
Catasetum complanatum
Catasetum discolor Catasetum longifolium - flower 1.jpg
Catasetum discolor
Catasetum expansum Catasetum expansum Orchi 01.jpg
Catasetum expansum
Catasetum fimbriatum Catasetum fimbriatum Orchi 05.jpg
Catasetum fimbriatum
Catasetum lendarium Orquidea Catasetum lendarium por Jani Pereira 3.jpg
Catasetum lendarium
Catasetum luridum Catasetum luridum - Flickr 007 (cropped).jpg
Catasetum luridum
Catasetum macrocarpum Catasetum macrocarpum L. C. Rich. - Flickr - Alex Popovkin, Bahia, Brazil (1).jpg
Catasetum macrocarpum
Catasetum macroglossum Catasetum macroglossum Orchi 085.jpg
Catasetum macroglossum
Catasetum maculatum Catasetum maculatum Orchi 092.jpg
Catasetum maculatum
Catasetum pileatum Catasetum pileatum Orchi 088.jpg
Catasetum pileatum
Catasetum saccatum A and B Larsen orchids - Catasetum saccatum 515-22.jpg
Catasetum saccatum
Catasetum tabulare Catasetum tabulare Orchi 016.jpg
Catasetum tabulare
Catasetum osculatum Catasetum osculatum Orchi 089.jpg
Catasetum osculatum

Natural hybrids

Catasetum x faustoi (=C. longifolium x C. osculatum) CATASETUM X FAUSTOI DSC0849.jpg
Catasetum x faustoi (=C. longifolium x C. osculatum)

References

  1. 1 2 Kew World Checklist of Selected Plant Families
  2. "Catasetum Rich. ex Kunth | Plants of the World Online | Kew Science". Plants of the World Online. Retrieved 2024-03-29.
  3. Letter 3340 – Darwin, C. R. to Oliver, Daniel, 7 Dec (1861), Darwin Correspondence Project, retrieved 2012-09-28
  4. Letter 3407 – Rogers, John (a) to Darwin, C. R., 22 Jan 1862, Darwin Correspondence Project, archived from the original on 1 September 2007, retrieved 2012-09-28
  5. Desmond, Adrian; Moore, James (1991), Darwin, London: Michael Joseph, Penguin Group, ISBN   0-7181-3430-3 page 510.
  6. The Orchids, Natural History and Classification, Robert L. Dressler. ISBN   0-674-87526-5

Further reading